This invention relates to magnetic recording media such as magnetic audio and video recording tapes, sheets and disks and, in particular, to magnetic recording media improved in their smooth-running properties and electromagnetic conversion characteristics.
When used in recording and reproducing operations, magnetic recording media, in particular recording tapes, are subjected to sliding contact with parts of recording/reproducing instruments, such as magnetic heads and guide rollers, at a high relative speed. Therefore, it is required that the recording media retain smooth-running properties for a long period of time and have a high level of durability.
Generally, in order to reduce the friction coefficient of the recording media and impart smooth-running properties thereto, certain lubricants have been added to the magnetic layers of media. Silicone oils are typical and well-known as lubricants for these purposes. So far as we know, however, silicone oils have never achieved satisfactory smooth-running properties in the media. In addition, silicone oils show commonly poor compatibility with the resins used as binders in the magnetic layers of media and, hence, tend to exude to the surface of the magnetic layer and to smear the instrument parts which come in contact with the surface.